1. Field of the Invention
A combinational power cord for multimedia use comprises at least one multimedia power device mutually connected to provide power and to enable data transmission among different multimedia devices. The combinational power cord is extensible to fulfill the data transmission requirements and connectivity of different multimedia devices.
2. Description of the Prior Art
As PC becomes popular, the development of multimedia contents accelerates. It is now common for a family to own more than two computers and other multimedia devices. These electrical appliances or electronics devices provide entertainment and convenience and bring computer technologies to our daily lives. The development of networking computers further provides more convenience and efficiency. Although it is quite straightforward in concept to connect various multimedia devices to network. It is often that many computers have built-in networking capabilities to help users to connect to Internet. However, it is complicate and difficult to establish network connections. In other words, a user has to route the wire/cable between furniture to connect the computer, making it not acceptable in terms of aesthetic viewpoint and easy to trap people. The user can choose to have professional builders to route the network cable, while this should need more efforts and cost. It is likely that users want to connect their devices to computers and let the devices control by computers, for example, to set the time for playing music through speakers or to turn on TV. To achieve these functions, users have to connect these multimedia devices to computers. Then again they might encounter the wiring problems as well. Although wireless techniques such as Infrared or RF have been proposed and used, there are certain deficiencies such as the transmitting range and angle, the EM interference between devices. Besides, there are other factors such as shielding effect and possible harmfulness to human bodies to consider.
Therefore, power line transmission has been proposed to convert digital signals and use power line carrier signals to send modulated signals since the power supply plays an important role in providing power to electrical appliances or electronics devices. Power outlets can be seen everywhere in every family or office to help to reduce the wirings or the need to add phone line and wired network sockets, therefore it is much easier to build a multimedia network.
Traditional power cords such as the ones disclosed in ROC patents No. 089112369 and No. 092208790 have fixed number of sockets and support a fixed multimedia format. They use sockets to interact with multimedia devices to provide multimedia signals and power to these electrical appliances and electronics devices. In actual use these power cords are not flexible in providing the number of sockets and the supported media types. In ROC patent No. 91212382, it discloses a power cord supporting one single multimedia device; the present invention is a modification of ROC patent No. 91212382 to provide a power cord, which can support multiple multimedia devices without the need to redesign.